What is the purpose of an EGR (Exhaust Gas Recirculation) system?

The purpose of an Exhaust Gas Recirculation (EGR) system is primarily to reduce nitrogen oxide (NOx) emissions from the engine. When the EGR system operates, it recirculates a portion of the exhaust gases back into the intake manifold. This process lowers the combustion temperature inside the cylinders, which significantly reduces the formation of nitrogen oxides. NOx emissions are a major contributor to air pollution and are tightly regulated by environmental laws.

By lowering the combustion temperature, the EGR system also helps improve overall engine efficiency while complying with emission standards. This is crucial for manufacturers to meet government regulations on vehicle emissions. Understanding the operation and benefits of the EGR system is essential for diagnosing and repairing emissions-related issues in vehicles.